Investigation 3 - Brine Shrimp - Amazing Survivors!

Overview: Students set up experiments to test their predictions about what brine shrimp eggs need to hatch and to grow. They make daily observations, ask questions, and record and share information.

Focus Questions:

• What are brine shrimp?
• Where do they live and why?
• What do their eggs need to hatch?
• What conditions do the larvae need to grow to adulthood?
• What do the adults look like and how do they act?

Engagement: (1-2 class periods)

Use language arts block time for this to allow sufficient science time (30-40 minutes) the same day to set up your hatcheries.

Engage students in a “read-aloud, think-aloud” of Disappearing Lake, by Debbie Miller.
Sitting in a circle will help make this an interactive learning experience.

During and after reading, make connections between this temporary Alaska habitat, a vernal pond where fairy shrimp hatch, and the brine shrimp we will be using for our investigation today. Brine shrimp live in extremely saline environments such as some tide pools, and the Great Salt Lake, but go into a dormant stage when conditions change temporarily.

Brine shrimp, also called "sea monkeys", have developed a way to survive when their habitat changes. They coat their dormant eggs with a substance called trehalose that keeps them alive until they are put in water again. (See background information on Sea Monkeys).
Draw a big circle on board and write “brine shrimp” inside. Ask kids to brainstorm everything they know about this animal which is a shrimp. Add their knowledge to this web or bubble map. You may want to add a few pre-selected facts to this semantic map. Don’t give them too much information about the characteristics of brine shrimp at the beginning; let them discover it through their investigations. Show the package of dry shrimp, pictures, or other objects related to the investigation.

Science notebooks. Ask students to draw a picture on the cover (or first page of the section) on the topic of brine shrimp and their habitat.

Exploration: (1 class period)

Ask students what they think the dormant eggs may need in order to hatch (such as water, air, heat, light, salt, etc.). Ask them to write a prediction in their science notebook.

Guide them toward setting up simple experiments, individually or in small groups, connected to their prediction. These “experiments” can be as simple as observations. They do not need to do all the steps of the scientific process we might expect older students to know about, but should be able to understand the idea of a “fair test.” 

Examples:
What do they need besides water to hatch?
Do they need light in order to come alive?
Will they hatch if the temperature is cold (or hot)?

Show and explain the basic materials that are available. Organize students into small groups or pairs to plan their investigation. Regroup in 10-15 minutes and ask students to draw/write about what they plan to do in their science notebook. Circulate around groups to offer suggestions. Have students set up the first investigation and leave it to sit overnight, since it will take 24 hours or 2-3 days at 77 degrees F for the cysts to burst out of their shells. Follow the directions that come with your eggs/cysts regarding the addition of salt or baking soda concentrations. A possible rule of thumb for creating a saline environment is to add 1-1½ teaspoon of non-iodized salt per cup of water. Help children mark the full water level on their bottle or jar the first day with a permanent marker, so they can refill it to the same level as water evaporates.

Explanation: (15 minutes per day for 2-3 days)

On the day after the experiment has been set up, have students observe the changes that happened overnight and record their observations in their science notebooks with drawings and sentences. Provide time to share and discuss results.

Observe and record daily or frequently throughout this investigation. When most have hatched, move on to “Elaboration.”

Elaboration (30 minutes, then 10 minutes per day for 6-10 days)

At 77 degrees F the embryo should molt 15 times and reach adulthood in about 8 days.
Ask students to write the date in their science notebook, and then copy or glue in this question:
What do the brine shrimp need to grow to become adults?

Ask them to make and write predictions, then guide the class in sharing their predictions.

Ask students to select from stations of habitat choices that you have set up to test student predictions.
Some possibilities are:

• If students predict that sea monkeys need light to grow, set up a station in which one jar has full light, one has partial light, and one is dark.
• If students predict that sea monkeys need warm water, set up a station in which one jar is warmed by a heat lamp or warm water “bath,” one is room temperature, and the other is kept cool with ice or snow.

Set up combinations such as warm/light, warm/dark, cool/light, cool/dark.

Students will make daily observations and record them in their science notebooks. Model and encourage them to make drawings with labels. They will need magnifying lenses to see the shrimp.

Feeding is not necessary if tiny green thread or spots (algae) start to grow in your container. If not, you can feed only once or twice a week, a few grains of powdered yeast. This could be mixed with some salt water from the jar and fed with an eyedropper.

Evaluation

A suggested daily evaluation of the science notebook would be a checklist of required steps for each day, with points given for completion of tasks. For a self-evaluation, ask students to flag or put a sticky on their “best” drawing or writing sample.

On the final day of this unit, have students talk about, then write, “What I Learned,” through drawing and writing. Encourage them to use all the “key” terms from the investigations that you have listed on the board, or they have written in their science notebooks, and come up with new questions. Review their notebooks throughout and at the end of the investigation, guiding their learning with comments and questions.

Teacher Preparation

Be sure to read this entire lesson, including Teacher Background Information first.

Purchase/order brine shrimp weeks in advance. These dehydrated eggs can be purchased for about $5.00 at pet stores, or ordered from online sites. (See Background Information for ordering sources).

Arrange a classroom space where brine shrimp bottles or jars will be safe for a few days during the exploration.
Organize materials for distribution to students.
Prepare a few “control hatcheries” in case there are casualties!
Set up habitat choice stations for the elaboration part of the investigation.

Curricular Connections

Writing. Creative writing opportunities may arise as students observe the movements of their creatures. They may want to name them and write stories or conversations about them.

Math. Activities might include graphing the results of brine shrimp growth under various conditions, measuring liquid and determining salt to add, and adding numbers.

Students also may practice the following skills to address math and language arts standards: write/draw descriptions of sequences and steps, follow oral instructions, estimate numerical answers.

Ideas for adapting to different local environment or context. Discuss whether animals that live in local ponds or wetlands that dry up seasonally or freeze solidly during winter would need a way to survive the change in their habitat. Have students research what happens to fairy shrimp, mosquitoes, aquatic insects, blackfish, wood frogs, or other aquatic animals when their habitats dry up or freeze. Consult elders and other local experts, including checking with your local offices of U.S. Fish and Wildlife , National Park Service, Alaska Dept. of Fish and Game, and other local agencies for educational programs and presenters on fish and wildlife habitats. 

Alaska Science Standards and Grade Level Expectations Addressed:

1st and 2nd grade standards addressed:
A1 - Science as Inquiry and Process
SA Students develop an understanding of the processes and applications of scientific inquiry.
SA1 Students develop an understanding of the processes of science used to investigate problems, design and conduct repeatable scientific investigations, and defend scientific arguments.
SA3 Students develop an understanding that culture, local knowledge, history, and interaction with the environment contribute to the development of scientific knowledge, and that local applications provide opportunity for understanding scientific concepts and global issues.

G1 – History and Nature of Science
SG Students develop an understanding of the history and nature of science.
SG2 Students develop an understanding that the advancement of scientific knowledge embraces innovation and requires empirical evidence, repeatable investigations, logical arguments, and critical review in striving for the best possible explanations of the natural world.
SG4 Students develop an understanding that advancements in science depend on curiosity, creativity, imagination, and a broad knowledge base.

3rd Grade GLEs addressed:
The student develops an understanding of the processes of science by:
[3] SA1.1 asking questions, predicting, observing, describing, measuring, classifying, making generalizations, inferring and communicating.
[3] SA1.2 observing and describing their world to answer simple questions.

The student demonstrates an understanding that interactions with the environment provide an opportunity for understanding scientific concepts by:  [3] SA3.1 observing local conditions that determine which plants and/or animals survive. (L)

The student demonstrates an understanding of the bases of the advancement of scientific knowledge by: [3] SG2.1 comparing the results of multiple observations of a single local event. (L)

The student demonstrates an understanding that advancements in science depend on curiosity, creativity, imagination, and a broad knowledge base by: [3] SG4.1 asking questions about the natural world.